Linux Process Management - S6

http://skarnet.org/software/s6/overview.html

S6 is a  process management tool , built from ground up. Based upon reliable libraries

https://skarnet.org/software/s6/why.html

Purpose : To manage any process inside a operating system , restart if needed.

Some examples of s6 programs meant to be used in run scripts:

• The s6-log program is a long-lived process. It is meant to be executed into by a ./log/run script: it will be supervised, and will process what it reads on its stdin (i.e. the output of the ./run daemon).
• The s6-envdir program is a short-lived process that will update its current environment according to what it reads in a given directory, then execute into the rest of its command line. It is meant to be used in a run script to adjust the environment with which the final daemon will be executed into.
• Similarly, the s6-softlimit program adjusts its resource limits, then executes into the rest of its command line: it is meant to set the resources the final daemon will have access to.
• The s6-applyuidgid program, part of the s6-*uidgid family, drops root privileges before executing into the rest of its command line: it is meant to be used in run scripts that need root privileges when starting but do not need it for the execution of the long-lived process.
• s6-ipcserverd is a daemon that listens to a Unix socket and spawns a program for every connection. It is meant to be supervised, so it should be used in a run script, and it's also meant to be a flexible super-server that you can use for different applications: so it is a building block that may appear in several of your run scripts defining local services.